Can I promote a pawn to queen if i haven't lost any rooks?

Question

so when a pawn makes it to the other side of the chess board without me losing my queen, usually we turn over a rook and use it as a queen, right? But what if I still have a queen and both rooks? Am I still allowed to get another queen?

Answer 1

Sorry for the question: 

What possible reason would anyone ever have to underpromote, i.e., to convert to anything other than a queen? 

I hope someone would be good enough to respond.

 

 

 

Answer 2

Sorry for the question: 

What possible reason would anyone ever have to underpromote, i.e., to convert to anything other than a queen? 

I hope someone would be good enough to respond.